In the twelfth timeline holorecord for Star Wars: The Old Republic, Jedi Master Gnost-Dural (Lance Henriksen) discusses The Great Hyperspace War and how it stands above all other wars in galactic history. From our YouTube channel:

And the accompanying blurb:

BTC 1347 When two hyperspace explorers stumbled onto the remote world of Korriban, they never could have guessed the chain of events they were setting into motion. Over the previous centuries, the Sith Empire had grown in size and strength, and Korriban was the very heart of its dominion. The reigning Sith Lord, Marka Ragnos, had just died, sparking a brutal power struggle between rivals Ludo Kressh and Naga Sadow. The explorers' arrival marked the first contact between the Republic and the Sith Empire, and it created at an opportunity to end the power struggle. Naga Sadow seized the moment and rallied the Sith for a pre-emptive strike against the Republic under his leadership. The ensuing series of battles saw the Republic nearly destroyed, but Naga Sadow's machinations ultimately backfired, and the Republic drove the Sith back to Korriban. The Supreme Chancellor then directed Republic forces to ensure the Sith never returned. by annihilating their civilization entirely a move which would ultimately come back to haunt the Republic centuries later.